We often hear people say that they consume vegetable oils and avoid animal fats because “animal fats are full of pesticides.” Some animal fats do test high in pesticides, notably butterfat in conventional milk, cheese and ice cream and certain types of seafood, especially catfish, lobster and mollusks. However in a recent survey, soy bean oil tested almost as high in DDT, TDE and DDE as milk fat. (Conventionally grown potatoes, sweet potatoes and carrots also tested high; fish contained levels four times greater than those in butterfat.1)
By now you know that consumption of vegetable oils is associated with many health problems, from cancer and heart disease to growth problems and learning disabilities in children. The answer to the problem of pesticides in animal fats is not to replace them with vegetable oils but to avoid commercial versions of these animal foods and choose pasture-raised, or at least organically raised, versions instead. And, as we have pointed out in these pages, vitamin A from animal fats and organ meats provides powerful protection against dioxins.2
One thing you will not find in animal fats like butter, egg yolks and meat fat is hexane. This food-grade gasoline is the dominant solvent used in oilseed extraction throughout the world. It is very volatile, flammable and explosive—causing many explosions and fires in vegetable oil plants, and even a few in fast food fryers.
The EPA now categorizes hexane as a HAP (hazardous air pollutant), included on the list of 189 toxic chemicals. Inhalation of hexane can damage the nervous system, leading to numbness in the hands and feet, followed by weakness in the feet and lower legs. Paralysis may develop with continued exposure. Most at risk are those working in closed industrial facilities with hexane- containing solvents and glues. At very high levels of hexane in the air, signs of damage to sperm-forming cells in male rats occur.3
But the big question for the average consumer concerns the effect of hexane when it is ingested. Government and industry have tended to gloss over potential problems. “Because cooking oils are processed with solvents containing hexane, very small amounts may be present in these products. However, the amounts in cooking oil are too low to have any effect on people.”4
As for whether hexane causes cancer, of- ficial statements show a similar lack of concern: “There is no evidence that exposure to hexane increases the risk of cancer in people. No reliable information is available on whether hexane causes cancer in animals.”5 This is because very few studies have been carried out to determine the carcinogenicity of hexane. One of the few did find an increase in liver cancer in female mice after exposure for two years; no increase was found in male mice or in rats of either sex.6
And there may be other adverse effects. According to the Material Safety Data Sheet for Hexane, the substance is “Harmful or fatal if swallowed.” Ingestion may produce abdominal pain, nausea and symptoms that parallel those of inhalation, including “lightheadedness, nausea, headache and blurred vision. Greater exposure may cause muscle weakness, numbness of the extremities, unconsciousness and death.” Interestingly, one fact sheet on hexane lists high blood sugar as a toxic effect.7 Gastroparesis (literally, paralysis of the stomach, in which the stomach cannot churn and digest food) is another reported effect.8
In 1997, researchers using a new technology found higher-than-expected levels of pentane, hexane, heptanes, octane and benzene derivatives in all six hexane-extracted samples of cooking oils tested.9 This means that humans may be ingesting greater amounts of these petroleum derivatives than previously thought.
And it means that animals are ingesting higher levels also. Hexane levels in solvent-processed vegetable oil residue used for animal feed can run as high as 0.5 percent, enough to create a known mild toxicity that precludes the use of solvent-extracted meal in a number of markets, such as pig feeding. (It kills baby pigs, whose digestive tracts are similar to those of humans.)10
Those consuming solvent-extracted commercial vegetable oils every day—and that includes all fried food like French fries and Chicken McNuggets, commercial salad dressings, and cooking oils—are subjecting themselves to longterm chronic exposure, the effects of which are anybody’s guess.
Because processing of fragile vegetable oils creates free radicals and other highly reactive breakdown chemicals, these products require the addition of potent antioxidants like BHT, BHA and—the latest entry—TBHQ. A list of adverse effects from these substances includes cancer in various sites, liver toxicity, kidney and bladder toxicity, depression of thyroid function, and changes in behavior.11 TBHQ, in particular, makes test animals susceptible to stomach tumors and causes damage to DNA.12
An internet search reveals reports of behavior changes in children, including decreased concentration and learning ability and “screaming fits, teary, really temperamental, like world war three, and waking at night,” on exposure to unlabeled BHA and TBHQ.13 These additives are also found in commercial lard and beef tallow, so purchase these from a farmer you know and trust! The presence of hexane and powerful antioxidants provides yet more reasons to avoid vegetable oils and products made with them.
- www.fda.gov/ora/compliance_ref/cpg/cpgfod/cpg575-100. html.
This article appeared in Wise Traditions in Food, Farming and the Healing Arts, the quarterly journal of the Weston A. Price Foundation, Summer 2008.